Method for forming design in a layered panel using a laser

ABSTRACT

A method for forming a design in a panel includes providing an outer panel layer on an inner panel layer to form a single composite panel including two layers. The design is then formed into the panel by forming voids in the outer layer. The voids are formed by exposing predetermined regions of the outer layer to a laser beam that burns, vaporizes or otherwise removes portions of the outer layer in each exposed region. The voids create the design by exposing the inner panel layer.

This application claims priority of U.S. provisional patent applicationSer. No. 60/118,620 filed Feb. 4, 1999.

TECHNICAL FIELD OF THE INVENTION

This invention relates generally to a method for forming a multi-coloredor two-toned decorative outer class A surface or first surface on a skinor panel.

INVENTION BACKGROUND

Currently, multicolored or two-tone decorative surfaces are produced onskins or panels by a number of different processes. In general, theseprocesses can be categorized as either coating methods such as painting;or infusion methods such as material pigmenting, i.e., mixing color intoplastics materials before the materials are formed into skins or panels.

Processes that employ infusion include slush mold processes wherepre-pigmented dry particulate plastic materials are cast against aheated slush mold surface. The cast materials melt on the heated surfaceto form a shell or skin. Various methods for producing multi-colored ortwo-tone decorative surfaces includes the use of one or more gaskets inthe slush molding process. According to one method, one or more gasketsare used to form a decorative surface on a plastic skin or panelcomprising at least two distinct separate areas of plastic material. Thegasket is pressed against a heated slush mold surface to separatecastings of different-colored charges of dry, particulate plasticsmaterial.

Another method for producing multi-colored or two-tone decorativesurfaces on skins or panels using pre-pigmented plastic materialsincludes the masking of certain areas on a heatable slush mold surface.According to this method, a first or “outer” layer is formed by castinga first plastics material against a portion of the heated mold surface.The masking is then removed and a second or “inner” layer is formed bycasting a second plastic material of a different color or shade againstthe outer layer and also onto the exposed areas of the heated moldsurface that had been masked during the first casting step.

Each of the above slush mold methods produces a plastic skin or panelhaving a composite two-tone outer surface. Because the two plasticmaterials forming the composite surface are cast against the same heatedmold surface they form respective outer surfaces that lie flush inrelation to each other. In other words, the composite surface is asingle-level, smooth surface.

It is also known, in certain automotive applications, for skins, such asseat upholstery, to include textured surfaces comprising a plurality ofsmall diameter cylindrical depressions or through-holes. The depressionsor holes formed in these skins are on the order of one millimeter indiameter and are closely spaced in a regular pattern across an entireouter exposed surfaces of such skins.

What is needed is a quick and accurate method for mass producing skinsor panels having multi-colored or two-tone designs on an outer surfaceof each skin or panel.

SUMMARY OF THE INVENTION

According to the invention, a method is provided for forming a design ina panel (12). The method includes providing an outer layer (16), aninner layer (18) and providing the outer layer (16) on the inner layer(18) in a layered disposition. The method further includes providing adesign (14) in the panel (12) by forming voids (17) in the outer layer(16) that expose the inner layer (18).

The voids (17) are provided in the outer layer (16) by exposingpredetermined regions of the outer layer (16) to a laser beam (32)capable of burning, evaporating or otherwise removing portions of theouter layer (16) in each exposed region. The employment of lasertechnology allows detailed designs to be created in the outer class Asurfaces of large numbers of like panels both quickly and accurately inan assembly line process.

BRIEF DRAWING DESCRIPTION

To better understand and appreciate the invention, refer to thefollowing detailed description in connection with the accompanyingdrawings:

FIG. 1 is a perspective view of a plastic panel having a design formedaccording to the inventive method;

FIG. 2 is a partial cross-sectional edge view of the plastic skin ofFIG. 1 before design formation;

FIG. 3 is a partial cross-sectional edge view of the plastic skin ofFIG. 1;

FIG. 4 is a schematic front view of the panel of FIG. 1 supported on aholding fixture and being lased by a laser beam from a laser gun, alaser controller and a laser drive mechanism constructed according tothe invention, an alternate holding fixture drive mechanism being shownin phantom;

FIG. 5 is a partial cross-sectional edge view of the plastic skin ofFIG. 1 with outer and inner layers bonded together by an adhesive; and

FIG. 6 is a perspective view of a panel having a tear seam formedaccording to the inventive method to aid in the deployment of an air bagfrom behind the panel.

PREFERRED EMBODIMENT DESCRIPTION

A two-tone design formed on and into an outer surface 10 of a plasticskin or panel 12 according to the inventive method is generallyindicated at 14 in FIGS. 1 and 3. According to the method, the skin orpanel 12 is first manufactured without a design as shown in FIG. 2. Theskin or panel 12 is manufactured to include at least two layers as shownat 16 and 18 in FIGS. 1-3. The two layers may completely overlap throughthe skin or panel, or may partially overlap in an area where the designis to be applied according to the invention. The two layers 16, 18comprise respective first and second materials of different appearance,preferably plastic materials. The difference in appearance between therespective first and second plastic materials may be due to differencesin any one of a number of different visually discernable attributesincluding but not limited to color, intensity, texture, pattern, gloss,and thickness.

As used herein, a difference in appearance may be visually discernablevia ordinary viewing with the naked eye or where more objectivity isdesired, discerhable via a difference in numeric values as measured byany industry accepted appearance measurement test. For color, differenceis preferably measured as the difference in any individual numericalreading obtained from a spectrophotometer using the CE 1976 L* a* b*scales. For texture, which includes attributes such as grain, orangepeel, and surface roughness, a profilometer is preferred to obtainnumerical differences. For gloss, a gloss meter is preferred to measuredifferences in degree of reflective light.

The skin component may be formed from one or more plastics materialsincluding but not limited to polyvinyl chlorides (PVC), thermoplasticurethanes (TPU), thermoplastic olefins (TPO), thermoset urethanes,polyesters, rubbers, polypropylenes, and polyethylenes. The layers 16,18 may be formed by any known method including but not limited tocasting, vacuum forming, blow molding, injection molding, rotationalmolding, and spray coating. The layers 16, 18 may each be formedseparately and then bonded together, or may be manufactured as a singlecomposition including two or more layers 16, 18. In the embodiment ofFIGS. 1-3 the outer layer 16 is of a light colored plastics material andhas a thickness of approximately 0.010″, but may be as little as 0.001″as in the case of a spray coating. The second or underlying layer 18shown in FIGS. 1-3 is of a darker colored plastics material and has athickness of approximately 0.040″. As shown in FIGS. 1 and 3, the areaswhere portions of the first or outer layer 16 have been removed leaveexposed the underlying, darker second layer 18. While plastic materialsare preferred, other materials which could be substituted in anycombination and in any relative position including but not limited totextiles, leather, metals, wood, and natural and synthetic resins.

After formation, the skin or panel 12 is transported from amanufacturing area to a laser station shown schematically in FIG. 4. Atthe laser station the skin or panel 12 is placed on a holding fixture 30and the outer surface 10 of a first 16 or “outer” one of the two layers16, 18 is exposed to a laser beam 32 produced by a laser beam generator34 of a laser gun 36 and delivered by a beam delivery mechanism 38 ofthe gun 36. The laser gun 36 may be connected to an electroniccontroller 40 programmed to provide and remove the laser beam 32 byeither energizing and deenergizing the beam generator 34 or by directingand redirecting or blocking and unblocking the laser beam 32 generatedby the beam generator 34. The controller 40 may also be programmed tocommand a laser gun drive mechanism 42 to move the laser beam 32 tovarious predetermined points on the panel 12 or to direct the laser beam32 toward some point away from the panel. The electronic controller 40may be programmed to move the laser beam 32 in accordance with apredetermined program to a predetermined series of positions adjacentportions of the outer surface 10 of the first or outer layer 16 of theskin or panel 12 that are to be removed to expose corresponding portionsof a second 18 or underlying one of the two layers 16, 18 in apredetermined pattern to form a desired pattern. In each position of thepredetermined series of positions the controller 40 then commands thelaser gun 36 to operate in such a way as to cause an emitted laser beam32 to burn away, evaporate or otherwise remove portions of the firstlayer 16 of the panel 12 to leave corresponding voids 17 that exposecorresponding portions of the second layer 18 beneath. As shown in FIGS.1 and 3, the laser beam 32 may also be caused to burn a short distanceinto the second layer 18 to insure that the second material is exposeddespite any variations in thickness in the first layer 16.

As shown in phantom in FIG. 4, a holding fixture drive 44 may beoperatively connected to the holding fixture 30 and/or the panel 12 inplace of the laser gun drive 42. In such embodiments the controller 40is connected to the fixture drive 44 and programmed to move the panel 12in accordance with a predetermined program to a predetermined series ofpositions holding portions of the outer surface 10 in the path of thelaser beam 32 to form the desired pattern.

The removed portions and resulting voids 17 may, be of anyconfiguration, size and number to create a desired decorative effect.The configuration of the voids 17 may include holes of various shapes,as shown at 20 in FIGS. 1 and 3; lines as shown at 22, FIG. 1; and/orlogos, or logo enhancements as shown at 24 in FIG. 1. In addition, anumber of voids 17 may be arranged to form a composite logo image orother design 14. The various configurations of voids 17 could, forexample, be formed on automotive seat covers or interior trim panels. Inother embodiments the voids 17 may be configured to provide decorationand/or first surface weakening of a supplemental inflatable restraint(SIR) door opening.

The skin or panel described above is preferably of a type used for avehicle trim panel. However, other uses include, but are not limited totoys, construction, furniture, luggage, or any other application wheresuch an aesthetic appearance or function is desirable.

As set forth in the claims, the method includes providing an outer panellayer 16 comprising a first plastic material and an inner panel layer 18comprising a second plastic material that is different in appearancethan the first material. The difference in appearance between the firstand second materials may be due to differences in any one of a number ofdifferent visually discernable attributes such as color, intensity,texture pattern, gloss, and thickness. The inner and outer panel layer16 s may be the inner and outer panels 12 of an automotive seat cover orof an interior automotive trim panel 12.

As shown in FIG. 5, in providing the outer layer 16 on the inner layer18 in a layered disposition, an adhesive 50 may first be providedbetween the outer and inner layers 18. Alternatively, the outer andinner layers 18 may be formed by casting the first and second materials,in powder or particulate form, against a heated mold surface in a slushmolding process.

A design 14 is provided in the panel 12 by forming voids 17 in the outerlayer 16 such that that the inner layer 18 is exposed and visiblethrough the voids 17. The voids 17 may be formed to create a desireddecorative effect by, for example, configuring the voids 17 to includeholes of various shapes such as linear shapes 22, logos or logoenhancements 24, composite logo images and/or designs 14 formed byproviding a number of voids 17 adjacent one another in a predeterminedpattern. As shown in FIG. 6, other embodiments may include a weakenedregion as shown at 46 comprising a plurality of voids 17′ provided in apattern 46 or a weakened region as shown at 48 comprising a singleelongated void 17′. Each of these weakened regions 46, 48 are formed inan outer layer 16′ of a multi-layer panel 12′ and define a supplementalinflatable restraint door opening.

The voids 17 are provided by exposing predetermined regions of the outerlayer 16 to a laser beam 32 capable of burning, evaporating or otherwiseremoving portions of the outer layer 16 in each exposed region. Adesired remaining thickness of the second material may be providedbeneath each void by causing the laser to burn through the outer layer16 and, controllably, a desired fixed depth into the inner layer 18.

The laser beam 32 is directed by connecting a controller 40 to a drivemechanism 42 that is operatively connected to either the panel 12 or alaser beam delivery mechanism 38. The controller 40 is programmed tocreate a predetermined design 14 by commanding the drive mechanism 42 tomove one of the panel 12 and the laser beam 32 in a predeterminedpattern relative to one another. The controller 40 is also programmed toturn off or redirect the laser when the laser beam 32 has cut to apredetermined depth in to the panel 12.

I intend this description to illustrate certain embodiments of theinvention rather than to limit the invention. Therefore I have useddescriptive words rather than limiting words.

Obviously, it's possible to modify this invention from what thedescription teaches. One may practice the invention other than asdescribed.

What is claimed is:
 1. A method for forming a design in a panel themethod including steps of: providing a panel outer layer; providing apanel inner layer; providing the outer layer on the inner layer in alayered disposition; providing a design in said outer layer by removingportions of the outer layer thereby resulting voids exposing the innerlayer providing the voids by exposing predetermined regions of the outerlayer to a laser beam capable of burning, evaporating or otherwiseremoving portions of the outer layer in each exposed region.
 2. Themethod of claim 1 in which: the step of providing an outer layer (16)includes providing a layer comprising a first material; and the step ofproviding the inner layer (18) includes providing a layer that comprisesa second material different in appearance from the first material. 3.The method of claim 1 in which: the step of providing an outer layer(16) includes providing an outer skin (16) for an automotive seat cover(12); and the step of providing an inner layer (18) includes providingan inner layer (18) of an automotive seat cover (12).
 4. The method ofclaim 1 in which: the step of providing an outer layer (16) includesproviding an outer skin (16) for an automotive interior trim panel (12);and the step of providing an inner layer (18) includes providing aninner layer (18) of an automotive interior trim panel (12).
 5. Themethod of claim 1 including the additional step of providing an adhesivebetween the outer and inner layers before the step of providing theouter layer on the inner layer, wherein the step of removing portions ofthe outer layer further includes removing corresponding portions of theadhesive.
 6. The method of claim 1 in which the step of providing theouter layer (16) on the inner layer (18) and the steps of providing theouter and inner layers (16, 18) include casting the first and secondmaterials against a heated mold surface.
 7. The method of claim 1 inwhich the step of providing a design includes removing portions of theouter layer in a predetermined pattern to create a desired decorativeeffect.
 8. The method of claim 1 in which the step of providing a designincludes removing portions of the outer layer to include holes ofvarious shapes.
 9. The method of claim 1 in which the step of providinga design removing portions of the outer layer in a pattern forming aweakened region in the outer layer defining a supplemental inflatablerestraint door opening.
 10. The method of claim 1 in which the step ofremoving material of the outer layer includes providing a desiredremaining thickness of the second material beneath each void by causingthe laser beam to burn through the outer layer and a desired depth intothe inner layer.
 11. The method of claim 1 in which the step of removingmaterial of the outer layer includes directing the laser beam byconnecting a controller to a drive mechanism that is operativelyconnected to one of the panel and a laser beam delivery mechanism of alaser gun, the controller being programmed to create a predetermineddesign by commanding the drive mechanism to move one of the panel andthe laser beam in a predetermined pattern relative to one another. 12.The method of claim 11 in which the step of removing material of theouter layer includes connecting a controller to the laser gun, thecontroller being programmed to turn off or redirect the laser beam oncethe laser beam has cut to a predetermined depth into the panel.